Questions about air in supply lines and deep well

Hi,
we starting getting air in our supply lines. We bled them out a couple times but I expect it will happen again.
I had a well technician come out today and I wanted to run his logic and prices by the educated.
First, I opened the water valve right at the tank and it sputtered, so I figured the air was getting in from the well
from reading up on it. He said the same thing that either it was the pump leaking air or the pipes. His recommendation
about the pipes was that if I had a leak in one spot, then the rest of the pipe may be in the same condition and might
as well replace all of it if that were the case. How do I know whether my pipe are metal or pvc? I would think if pvc,
it shouldn't be affected by water the way that metal is. He said the price of the pipe would be about $70 for a 21 foot section.
If we replaced all of it then he'd give a better price. I know that pvc for this application is maybe about 70 cents a foot, so do
you think he's talking about galvanized pipe? My house was built in 2001 and is in central Florida. If I have galvanized and it's leaking,
can I replace it with pvc?
To prove to me that there was air in the well, he unscrewed the pipe coming from the wellhead going to the tank. He then
turned on the motor and asked me to listen to the water coming up. It came out pretty quickly like maybe a second, but it did sound
like it was coming up with a gurgling sound. He then
put his hand over the pipe and said that if the water was falling it would create suction on his hand. I could hear the suction
as he removed his hand. He was able to do that several times. So, that all sounds logical to me. If there were no air leak then
the water should be right at the top of the pipe. Does that all sound right?
He said that if it is the pump, he would replace it for $1200 installed. The replacement pump is a 1.5hp 230v Franklin Submersible.
I didn't know that there were different flow rates til a few minutes ago reading another thread in this forum. I'm not sure what my existing pump flow rate is. I have the old style 220 gallon tank.
He also said I should get rid of that and get an 80 gallon bladder tank. Are Franklin pumps any good and should I watch out for different
models that may be ultra cheap, as in different flow rates, etc?

He said that he didn't think my current tank was working properly for that reason.
Sorry, I neglected to note that fact. I see a pressure gauge on the tank but nothing else.
I'll go look at it again to be sure. Could it be that an AVC should have been installed and just wasn't?
I'll have to google some of these terms because I don't know what they look like.
Thanks for responding.

Here's what I see on the tank:
1. A large screw on the top, like maybe 1.5 inch diameter.
2. a small square bolt on the front side near the top of the unit. I'm assuming that's
a blowout bolt or something in case of over-pressurization. Feel free to correct me.
3. The pressure gauge on the front side beneath that smaller square bolt.
The outlet pipe has a garden hose sized spigot attached. Something like a small vertical section
of pipe is above the spigot wrapped in insulation.
Question - since I have steel connectors above and connected to the well cap, does that mean
I have galvanized pipe beneath the well cap and down to the water? Or could it be pvc from there?

You may have a bleeder plug in the drop pipe someplace which is sucking air through an uncapped snifter valve. If the AVC isn't working properly, your tank will eventually become air bound and blow air out through the faucets.

$70.00 for sch 80 pvc is pretty steep, but about right for steel.

Franklin makes a good stainless steel pump, but I don't care for their plastic pumps. Or anyone else's either for that matter.

You may have a bleeder plug in the drop pipe someplace which is sucking air through an uncapped snifter valve. If the AVC isn't working properly, your tank will eventually become air bound and blow air out through the faucets.

$70.00 for sch 80 pvc is pretty steep, but about right for steel.

Franklin makes a good stainless steel pump, but I don't care for their plastic pumps. Or anyone else's either for that matter.

Get rid of that galvanized nipple under the pressure switch.

Click to expand...

I wasn't aware of a bleeder plug or the snifter valve, but I read up on it and seems it's common for this type of system.
Do you have to pull all the pipe to check that?
And let me ask a simpler question. My well guy said the air is leaking in from
only one of two places: a hole in the pipe or through the pump. I asked about a bad check valve because
I thought I read that somewhere.
I think you're telling me that the air can also be leaking in through a bleeder plug?
Is there always a check value inside the well?
Oh, also if I "get rid of the galvanized nipple beneath the pressure switch", what do I use in its place?
And what is the problem with it to begin with?

I think the galv nipple may have caused the pressure switch to fail as you said.
The technician stuck a piece of wood in the gap to disable it. When he wanted to re-enable
it, it would not work. So, he had to replace it.
What should be the course of action beyond fixing the AVC?
What do you suspect is the most likely cause?

I've been reading up some. This video was very helpful since it is showing the design that craigpump is talking about.http://www.youtube.com/watch?v=sIlkKHkUYGg
As these guys were installing the new pump, there was pvc to the pump and then copper
and brass fittings around the bleeder valves. Is that typical?
One thing I have no clue about yet is whether I have a pitless adapter in my system.
How would I know?

If it ain't broke, why fix it? Leave the well alone unless you want to replace the entire system. The problem is the AVC. If it is too badly rusted to remove, leave it alone and add a second smaller hydro-pneumatic tank downstream to remove the air.

If you manually drain and bleed the system, how long does it take before it spits air again?

Too much air in the pressure tank will permit large bubbles to be carried into the piping system. This causes a disagreeable noise and sputtering at the faucets. It is the function of U.S. Gauge air volume controls to maintain the correct relationship between the volume of air and the quantity of water in the pressure tank.

Those are my precise symptoms, so after knowing this I'm more on-board than over to replace this valve before doing anything else.
Is this common knowledge that a bad AVC valve on a pneumatic tank can cause sputtering / air in the supply lines?
Is it hard to replace; i.e. can I do it myself?

If it ain't broke, why fix it? Leave the well alone unless you want to replace the entire system. The problem is the AVC. If it is too badly rusted to remove, leave it alone and add a second smaller hydro-pneumatic tank downstream to remove the air.

If you manually drain and bleed the system, how long does it take before it spits air again?

Click to expand...

I'm totally on-board with fixing only what's busted. The spurting has only occured twice and started about two weeks ago.
We only drained and bled the system yesterday, so I don't know how long it will be. When it happened the first time,
it helped to open all faucets in the house and running the water for about 15 minutes. That got rid of the spurting "mostly"
for about a week, but even after a few days I started to hear the spurting.
How would I know if the AVC is too badly rusted to remove?